A strain of actinomycetes identified as Saccharothrix sp. SANK 64289 was found to produce new antibiotics, galacardins A and B. Their physico-chemical properties showed that they were new members of glycopeptide antibiotics. They were structurally related to beta-avoparcin but differed from it only in sugar composition. Though beta-avoparcin does not contain galactose, galacardins A and B did contain two and one moles of galactose, respectively. They showed strong antimicrobial activity against Gram-positive bacteria and also showed excellent in vivo protective activity against Staphylococcus aureus infection in mice.